1. Field of the invention
The present invention is related to an antenna assembled by actions of vacuum and static electric attraction; and especially to an antenna of which the assembling process of an insulating sleeve and an inner connecting rod will make generating of static electric friction and vacuum attraction to result fixed engagement between the two elements directly.
2. Description of the Prior Art
Most antennas such as the fixed-type antennas used in mobile phones use interior helical coils as the main elements for transmitting and receiving frequency. The bottom of a helical coil on the one hand is connected with a metallic connecting seat, and on the other hand is positioned, sheltered and insulated by an inner connecting rod and a sleeve related therewith.
In such a conventional structure of fixed-type antenna for a mobile phone, the bottom of the helical coil firstly can be connected with the metallic connecting seat and positioned by means of the insulated inner connecting rod, and then the sleeve is mounted (it is generally called as a cap portion). This kind of combination structure can be further combined through a high frequency welding process or the like. Or in another kind of manufacturing method, the related elements of the positioned helical coil and metallic connecting seat will be placed in a mold, and then the sleeve is shaped by ejection-enveloping procedure. However in this structure processed, it is less convenient to have the preliminarily assembled elements installed in a mold, as a necessary procedure, for processing on the one hand; and the speed of the mass production will be slowed down by that every product in the production process has to be put in the mold on the other hand.
The object of the present invention is to provide a structure of an antenna assembled by actions of vacuum and static electric attraction. After an inner connecting rod (used to position a helical coil) and a sleeve are shaped separately, the two will engage firmly with each other by static-electric friction and vacuum attraction in a fast and direct manner. This can thereby increase the efficiency of mass production of the antenna.
In order to obtain the abovementioned purpose, the sleeve in this invention has an upper closed end, a bottom opened end and an inner bore with a plurality of sections with their diameters gradually enlarged from the inside to the outside. There are two or more than two inner annular recesses provided longitudinally along the inner bore sections. A plurality of rod sections and annular protrusions with identical cross-sections respectively to those of the annular recesses are provided on the inner connecting rod at the positions respectively corresponding with the abovementioned inner bore sections, the inner connecting rod can be inserted in and matched with the inner bore through an bottom opening. The abovementioned sleeve and inner connecting rod are made of the material of different coefficients of friction, and the connecting surfaces of the two elements are polished to become smooth surfaces so as to generate vacuum and static electric attraction to create mutually engaging force in the insertion connecting process.
Under the condition that the insertion connecting elements are made of material of different friction-coefficients as is mentioned above, One of the insertion connecting elements can be made of silicone or mixed material of rubber and plastic, the other insertion connecting element can be of pure plastic material.
The present invention will be apparent in its novelty and other features after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.